US2282658A - Sanding belt machine - Google Patents

Description

M y 2, 1942. R. F. KNEISLEY 2,282,658

SANDING BELT MACHINE Z-- Filed Jan. 27, 1941 I 2 Sheets-Sheet 1 May 12, 1942 R. F. KNEISLEY SANDING BELT MACHINE Filed Jan. 27, 1941 2 Sheets-Sheet 2 gwucm tor,

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Patented May 12, 1942 SANDING BELT MACHUINE Richard F. Kneisley, Toledo, Ohio, assignor to The American Floor Surfacing Machine Company, Toledo, Ohio, a corporation of Ohio Application January 27, 1941, Serial No. 376,012

7 Claims.

This invention relates to surfacing machines, and particularly to those of the sanding belt type, and this application is a continuation in part of my prior application for Sanding belt machine, filed July 10, 1940, Serial No, 344,809.

The primary object of the invention is the provision of an improved machine of this character which is of small, light and compact construction to adapt it for hand use in the sanding of boats, walls, machines and other objects, and is highly efficient in use.

A further object of the invention is the provision of certain features of construction and arrangement of parts which both separately and collectively contribute to the features of compactness, appearance and efiiciency of the ma- The invention is fully described in the following specification, and a preferred embodiment thereof illustrated in the accompanying drawings, in which- Figure 1 is a side elevation of a machine embodying the invention, with parts broken away; Fig. 2 is a vertical section on the line 2-2 in Fig. 1, with a part in full; Fig. 3 is a detailed enlargement of a portion of the section shown in Fig. 2; Fig. 4 is an enlarged section on the line 4-4 in Fig. 1; Fig. 5 is a fragmentary vertical section on the line 55 in Fig. 2, with apart in full; Fig. 6 is a vertical section on the line 6-6 in Fig. 1; Fig. '7 is a fragmentary section on the line 1-1 in Fig. 1; Fig. 8 is a vertical section similar to Fig 2, with a slightly different form of mounting for the rocker member and with a part in full; Fig. 9 is an enlarged fragmentary portion of the section shown in Fig. 8, and Fig. 10 is a section on the line Ill-40 in Fig. 9.

Referring to the drawings, l designates a hollow housing adapted to enclose the operative parts of the machine, with the exception of the exposed working portion of the sanding belt 2. This housing is preferably increased in depth from one end to the other, the front end, in the present instance, being of the greatest depth, and is closed at its top and ends and at one side, the left in the present instance. The opposite side of the housing is open to permit access to the parts within the housing and is closed by a removable side plate 3 adapted to have snap engagement at its edges with registering portions of the housing walls. A removable cover plate 4 cooperates with a flanged portion 5 of the closed side of the housing to form a gear compartment 6.

Disposed within the housing I substantially centrally thereof, and in the present instance 5 formed integrally with the closed side wall thereof, is a horizontally disposed cylindrical field frame 8 of an electric motor. The armature H) of this motor has its shaft II disposed crosswise of the housing I axially of said field frame, and journaled at one end in a suitable bearing in the closed side of the housing land at its other end in a cover I2 secured to and closing the outer open end of the field frame. The frame 8 is formed at its under side with a fiat bottom boss l3 to which a foot or pressure plate [5 for the workin portion of the sanding belt is secured in any suitable manner, as by screws (not shown). This foot plate I5 extends in both directions from said boss toward the respective ends of the housing I, but terminates short thereof. The ends of this plate are preferably turned inwardly, as shown,

The motor commutator brushes ll are removably mounted, in any suitable manner, in upper and lower sockets I8 in the housing. A ventilating fan I9 is carried by the armature shaft ll within the field frame cover I2 and the ingress and egress of air to and from the motor is provided through suitable openings in the housing and cover.

The armature shaft II at the closed side of the housing 1 extends within the gear chamber 6 and carries thereina drive pinion 20 in con nectiomthrough intermediate gears 2|, 22, on a stub shaft 23, with a gear 24 on a shaft 25. The shaft 25 is disposed crosswise of the frame at the rear of the motor field frame 8 and is journaled in a boss 21 projecting into the housing from its closed side, as best shown in Fig. 7. The drive drum 30 for the sanding belt 2 is mounted on the shaft 25 to be driven thereby and preferably has its periphery faced with a friction material. 3i to facilitate driving the sanding belt without slipping.

' The sanding'belt 2 is guided at the rear end of the machine by the drum 3!] and at the for ward end thereof by the vertically spacedidler rolls 32 and 33 with its upper and lower runs above and below the field frame 8 and with its lower run extending under and guided by the foot or pressure plate l5. It is thus apparent that the motor is disposed within thebelt, so that it is only necessary tomake the housing I of sufli cient size to enclose the belt and its guide mem? bers. I

The idler roll 32, in the present instance, .is fixedly carried bya shaft 34 which is journaled in a boss 34 projecting inward from the closed side of the housing I at the lower forward corner por- 33 and to provide spaced bearings for the shaft 31 V on which the roll is mounted. The rocker member 35 is urged outward to apply yielding tension to the belt by the action of a coiled expansion spring 38 interposed between the member and the adjacent side of the field frame 8 and seating atits respective ends thereagainst, as best shown in Fig. 5.

Mounted in the closed side of the housing adjacent to the side edge of the rocker member 35 is a shaft 39 which is provided at its inner end with an eccentric stud 40 for engagement with a web 4| on the side edge of the rocker member, as shown in Fig. 2. The shaft 39 is provided at its outer end with a control handle '42 of lever form which may be raised when it is desired to swing the member 35 inward against the tension of the spring 38 to facilitate changing the belt.

The rocker member 35 is mounted at its inner end on a shaft divided lengthwise into the sections 0. and b with the axes of said sections intersecting at a very slight angle, so that a turning of the shaft about the axis of the section a will impart a revoluble movement about such axis. The shaft portion a is journaled in a boss 46 in the closed side of the housing I, and at the outer side of the housing is provided with a knob 41 to facilitate turning for effecting a rotary adjustment of the shaft. projects from the inner end of the section a at a very slight angle thereto and is of sufiicient length for the inner end of the rocker member 35 to be mounted thereon for free rocking movements lengthwise of the machine; While the member 35 is adapted to rock on the shaft 45 about its axis, it has a sufficiently close fit on the shaft to prevent lateral rocking movements of the member on the shaft. The purpose of this manner of mounting the rocker member is to provide a tracking adjustment for the sanding belt, so that the rocker member may be given a slight tilt transversely of the housing, in one direction or the other, to cause the belt to tend to move slightly one way or the other .on the roll 33 lengthwise thereof, as is apparent. It will be understood that in practice the tilting angle of the member carrying portion b of the shaft 45 relative to the portion a thereof is very slight and that the showing in Fig. 2 in this respect is greater than in actual practice. The enlargement in Fig. 3 shows the angular relation of the shaft parts a and b more as they are in practice.

It is found in practice that the tendency of the sanding belt to run one way or the other transversely of the machine is due to various causes, and that it is frequently very difficult to tell what it is that prevents the belt from properly tracking on the guide pulleys. It sometimes happens that The portion b of the shaft after removing a belt from the machine and then I adjustment of the rocker member 35.

housing I, this is usually readily noticeable by the operator, but if the movement is toward the closed side of the housing, it is very difficult to determine the extent of such movement and whether or not the belt is being injured by and is doing damage to the inner closed side of the housing due to the rubbing of one against the other. Such a rubbing or frictional engagement of the inner edge of the belt with the housing side not only wears and distorts the edge of the belt at such side, but it also causes a wearing away of the housing at the point or points of engagement which frequently extends through the side of the housing, forming a hole or holes therein. Such damage to the housing can only be remedied by patching, which is usually objectionable, or by replacing the housing with a new one, which is expensive.

In order to prevent the wear on the housing by contact of the inner edge of the belt therewith, the housing is provided on its inner side wall with two washers 50 disposed at opposite sides of the pulley 33 and removably carried by screws 5|.

threaded into bosses 52 on the inner side of the housing, as shown in Figs. 1, 4 and 5. These washers are positioned for the edge of the belt 2 to contact therewith when it has moved a predetermined extent toward the adjacent side of the housing and the turning of the washer reduces friction and wear. When these washers have been worn to a considerable extent they may be easily replaced. When the machine is operated with the side cover 3 removed, the washers 50 may be easily viewed and the operator can thereby determine if the belt is tracking too much toward the closed side of the housing, this being perceptible by reason of the movement imparted to the washers by the belt. While this is a simple feature, it is found important and of considerable value from a commercial standpoint and in facilitating a proper operating of the machine.

In Figs. 8, 9 and 10 is illustrated a slightly modified means for effecting a transverse tilting This mounting means comprises a pin 55 on which rocker member 35 is mounted on its inner end and which itself is fixedly mounted at its inner end in a boss 56 in the closed side of the housing ,I. The member 35 has its inner edge relative to the housing provided with a, fairly loose fit on said pin, as shown at 51 (Fig. 9), while its outer edge portion is mounted on an eccentric bushing 58, which in turn is mounted for rotary adjustment on an eccentric stud 59 at the outer end of the pin 55. The bushing 58 is secured in adjusted position on the eccentric 59 by a nut 60 threaded onto the outer end of the eccentric. It is apparent that a turning of the bushing 58 On the eccentric 59 will impart a transverse tilting to the member 35 relative to the axis of the pin 55 in one direction or the other so as to correct any tendency of the belt to improperly track on the guiding post.

It is apparent that I have provided a small type of hand sanding machine with the parts compactly and efficiently arranged, with a simple and efficient tracking adjustment feature for the sanding belt and with means disposed at the inner side of the housing to indicate improper movement of the belt toward such side and to prevent resulting injury to the housing.

Iwish it understood that my invention is not limited to any specific construction, arrangement or form of the parts, as it is capable of numerous gamete modifications and changes without departing from the spirit of the claims.

Having thus described my invention, what I claim as new, and desire to secure by United States Patent, is:

1. In a machine of the class described, a housing having its top, one side and ends closed, an electric motor disposed substantially centrally within the housing with its armature shaft axis transverse thereto, said motor having a cylindrical field frame integral with and projecting into the housing from the closed side thereof, the under side of said frame forming a flat bottom boss, a pressure plate secured to the under side of said boss and projecting in both directions therefrom lengthwise of the housing, a shaft bearing plate secured to the outer end of said field frame, the armature shaft of the motor being journaled at one end in the closed side of the housing and at its other end in said bearing plate, a sanding belt extending around said field frame and having its run under said pressure plate, a drive and guiding drum for said belt in one end of the housing, vertically spaced belt guiding and tension rolls in the opposite end of the housing, means disposed within the closed side of said housing for driving said drum from said motor, and means for closing the open side of said housing.

2. In a machine of the class described, a onepiece housing having its top, one side and ends closed, an electric motor disposed substantially centrally within the housing with its armature shaft transverse thereto, said motor having a cylindrical field frame formed integral with and projecting into the housing from the closed side thereof, a shaft bearing plate secured to the outer end of said field frame, the armature shaft of the motor being journaled at one end in the closed side of the housng and at its other end in said bearing plate, a sanding belt extending around said field frame and having an exposed run under said frame, a drive and guiding drum for said belt in one end of the housing, vertically spaced belt guiding and tension rolls in opposite ends of the housing, means disposed within the closed side of said housing for driving said drum from said motor, and removable means for closing the open side of said housing.

3. In a machine of the class described having a housing, and a sanding belt and guide means for the belt in said housing, said means including a tension roll, a rocker member carrying said roll at its outer end and mounted at its inner end for rocking movement lengthwise of the housing, a manually operable shaft rotatably mounted in said housing and extending transversely therein and having a portion within the housing slightly angled relative to the mounting portion of the shaft and constituting a mount for saidrocker member, said shaft when rotated efiecting a transverse tilting of the member to cause a belt tracking adjustment of the roll.

4. In a machine of the class described having a housing, and a sanding belt and guide means for the belt in said housing, said means including a belt tension roll, a rocker member carrying said roll at its outer end, means carrying said member at its inner end for rocking movements lengthwise of the housing to tension the belt and for tilting movements transverse to the housing to correct improper belt tracking, said means including a shaft having a portion rotatably journaled in a side of the housing and a portion slightly angled relative to the axis of said first portion and on which said member is mounted and which imparts a transverse tilting movement to said member when the shaft is,

turned. V V

5. In a machine of the class described having a sanding belt and guide means for the belt, said means including a tension roll, a rocker member carrying said roll and having transversely'spaced bearings at its inner end, a mounting pin for said member forming one bearing for the member and having an eccentric stud at its outer end, an eccentric bushing rotatably mounted on said stud and forming the second bearing for said member and being adjustable to efiect vtransverse tilting of the member to effect a belt tracking adjustment of the roll.

' 6. In a machine of the class described wherein a sanding belt is guided by a plurality of rolls within a housing, a rocker member carrying one of said rolls for swinging movement transverse to its axis and the axes ofthe other rolls, means urging swinging-movement of said rocker member in one direction to tension the belt, and

means spaced from the axes of the several rolls and forming a mounting within the housing for said rocker member and including at least one part about which said member has its rocking movements and which is rotatably adjustable relative to the rocker member in a plane transverse to its rocking axis to tilt its roll axis relative to the axes of the other rolls to cause a belt tracking adjustment of the roll carried by said member.

7. In a machine of the class described having a housing, anda sanding belt and guide means for the belt in said housing, said guide means including a tension roll, a rocker member carrying said roll and mounted in the housing for member about an axis transverse to the rocking.

plane of the member to effect a tilting of the rocking axis of the member relative to the housing and cause a belt tracking adjustment of the tension roll.

RICHARD F. KNEISLEY.

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